Russell E. Lewis
Associate Professor of Infectious Diseases
Department of Molecular Medicine
University of Padua
{{< fa solid envelope size=1x >}} russelledward.lewis@unipd.it
{{< fa brands github size=1x >}} https://github.com/Russlewisbo
What are the most common infections associated with short versus prolonged neutropenia?
How does the presentation of skin, mucocutaneous lesions, abdominal pain or pneumonia change the infection differential diagnosis?
What are common empiric antimicrobial regimens used
Virtually all antineoplastic impair proliferation of normal hematopoietic progenitor cells
Obliteration of the mitotic pool
Depletion of the marrow reserve
Antineoplastic drugs, glucocorticoids and irradiation also interfere with the function of non-proliferating granulocytes, resulting in:
Decreased chemotaxis
Diminished phagocytic capacity
Defective intracellular killing
Glucocorticoids seem to enhance granulocytopoiesis and mobilize the marginal and marrow pool reserve, but…
reduce accumulation of granulocytes at site of infection (reduced adherence)
diminished chemotactic activity
decreased phagocytosis and intracellular killing
| Source | Molecules | Active against |
|---|---|---|
Polymorphonuclear leukocytes (PMNs)
|
Lysozyme, myeloperoxidase, defensins, BPI, lactoferrin | Bacteria, fungi Bacteria, fungi |
| Macrophages | Similar to PMN but no myeloperoxidase Nitric oxide Arginase |
Intracellular pathogens (depletes arginine) |
| Eosinophil | Cationic proteins Major basic protein Peroxidase |
Worms (extracellular) |
| Natural killing cells | Perforins Granzymes |
Viral or bacterial infected cells |
% of patients who have a neutrophil count/mm3 of:
| Signs and Symptoms | <100 | 101-1000 | >1000 |
| Fever | 98 | 90 | 76 |
| Fluctuance | 6 | 36 | 52 |
| Fissure or ulceration | 21 | 42 | 54 |
| Exudate | 11 | 64 | 91 |
| Purulent sputum | 8 | 67 | 84 |
| Pyuria | 11 | 63 | 97 |